1. Field of the Invention
The present invention relates to an information processing apparatus and method for processing data which is input through a coordinate input device, a computer-readable memory, and a program.
2. Description of the Related Art
A so-called signature authentication system has been well known which uses a signature to verify the authenticity of a user. Such a system typically employs a signature authentication method as disclosed in Japanese Patent Laid-Open No. 10-143668 and No. 10-171926 entitled “HANDWRITTEN CHARACTER STRING VERIFICATION METHOD AND APPARATUS.” In this method, user writing data functioning as a password is used to verify a handwritten character string. Unlike passwords, however, writing data contains features specific to individuals, and others who enter the same word as that of one person might not be verified. The features include the shape of the written character, character writing order, character writing speed, and rhythm.
In this signature authentication method using a handwritten character string verification technique, an input device, known as a digitizer, is used to input signature data of a user to a computer in order to perform signature authentication. The handwritten character string verification technique is achieved by dynamic programming (DP) matching time-series data, such as coordinate data, writing pressure data, or writing speed data, which is captured using a digitizer, with the registration data that has been registered in a verification dictionary.
As further disclosed in Japanese Patent Laid-Open No. 9-81518 and No. 9-81519 entitled “VERIFICATION METHOD ON NETWORK,” writing data is exchanged on a server-client system, allowing the same writing data to be used as a password in different environments such as homes and offices.
In the related art, techniques using a digitizer include a handwritten character recognition technique to recognize handwritten characters plotted with pens, and a handwriting word processor in which characters or pictures plotted with pens are filed as data.
However, such a signature authentication method in the related art has caused a large difference in quality of the captured writing data depending upon the capabilities of the digitizers. In particular, in a client-server system, the signature authentication method has experienced a problem in that a user does not always use the same digitizer in the client, and the writing data transmitted from the client to the server may sometimes greatly differ. Digitizers having different processing rates would make the detected coordinates different, and the signature data itself may therefore be different, thereby prohibiting satisfactory authentication.
A handwritten character recognition technique and a handwriting word processor (handwriting stroke database) technique also have a problem in that the performance depends upon the capability of the digitizer.